Respiratory Distress Syndrome (RDS) in Newborns

Definition and Pathophysiology

Respiratory distress syndrome is a respiratory disorder of preterm newborns caused by surfactant deficiency, leading to alveolar collapse, impaired gas exchange, and characteristic clinical and radiographic findings, as noted by the American Thoracic Society 1, 2
High alveolar capillary permeability allows serum proteins to leak into airways, further inhibiting surfactant function, according to the American Journal of Respiratory and Critical Care Medicine 3

RDS predominantly affects premature infants, with the highest incidence in those born at less than 30 weeks gestation and weighing less than 1,000 g, as reported by the American Journal of Respiratory and Critical Care Medicine 4
Multiple gestation pregnancies are a risk factor for RDS, as noted by the American Journal of Respiratory and Critical Care Medicine 4
Absence of antenatal corticosteroid administration is a risk factor for RDS, according to Praxis Medical Insights 5

Antenatal corticosteroids are the most effective preventive intervention, working synergistically with postnatal surfactant to reduce mortality, severity of RDS, and air leaks, as recommended by Praxis Medical Insights 5
Early initiation of CPAP at or soon after birth is recommended as first-line prevention for preterm infants at risk of RDS, according to Praxis Medical Insights 5
Surfactant replacement therapy is the cornerstone of RDS treatment, significantly reducing mortality and respiratory morbidity in preterm infants with surfactant deficiency, as noted by Praxis Medical Insights 5

RDS is the primary precursor to bronchopulmonary dysplasia (BPD), a chronic condition that usually evolves after premature birth and respiratory distress syndrome due to surfactant deficiency, as reported by the American Journal of Respiratory and Critical Care Medicine 1
Airway obstruction and airway hyperreactivity persist into childhood in survivors, with average FEV₁ about 80% of control subjects at 6-15 years of age, according to the American Journal of Respiratory and Critical Care Medicine 6
CLDI predisposes to abnormal lung function in childhood independently from premature birth alone, as noted by the American Journal of Respiratory and Critical Care Medicine 6

The American Heart Association recommends starting with CPAP (5-6 cm H₂O) immediately after birth for all spontaneously breathing preterm infants with respiratory distress, rather than routine intubation, as CPAP prevents atelectasis by maintaining functional residual capacity and preventing alveolar collapse 7, 8
CPAP is less invasive than intubation and reduces the combined risk of death or bronchopulmonary dysplasia compared to immediate intubation 7, 8

The American Heart Association suggests using PEEP during positive pressure ventilation for premature newborns to prevent lung collapse at end-expiration, as PEEP maintains lung volume and improves oxygenation by preventing alveolar collapse 7, 8, 9
Gentle ventilation strategies minimize barotrauma and oxygen toxicity that contribute to bronchopulmonary dysplasia, with evidence from the American Journal of Respiratory and Critical Care Medicine 10

The American Journal of Respiratory and Critical Care Medicine reports that chronic lung disease of infancy represents the final common pathway, characterized by alveolar simplification in the modern era rather than the fibrosis seen historically, with multisystem complications beyond the respiratory system being common in these infants 10

The American Academy of Pediatrics recommends that surfactant deficiency is the primary mechanism causing respiratory distress syndrome in extremely preterm infants at 27 weeks gestation, leading to widespread atelectasis and impaired gas exchange 11

Infants born at or earlier than 27 weeks gestation have the highest incidence of RDS, with 90-92% requiring surfactant therapy even when exposed to antenatal steroids, according to the American College of Obstetricians and Gynecologists 12, 13, 14
The American Thoracic Society notes that at 27 weeks, the incidence of respiratory distress syndrome is not reduced after exposure to antenatal steroids, although severity may be somewhat lower 12, 13, 15
The use of prophylactic or early rescue surfactant (within 2 hours of birth) significantly reduces mortality (RR 0.61, NNT 22), pneumothorax (RR 0.62, NNT 47), and the combined outcome of bronchopulmonary dysplasia or death (RR 0.85, NNT 24) in infants <30 weeks gestation, as recommended by the Neonatal Resuscitation Program 14, 16
Surfactant replacement reduces overall mortality by 47% (RR 0.53, NNT 9) in preterm infants with surfactant deficiency, according to the American Academy of Pediatrics 11, 15, 17